The central aim of the proposed research is to develop Spatial Frequency Domain Imaging (SFDI) as a method that will provide objective parameters that can be used to non-invasively assess severity of burn wounds. Accurate determination of burn severity and extent, particularly with respect to partial thickness burns, is one of the major challenges that face any clinician or surgeon in deciding course of treatment of burns. The primary method of determining burn depth and severity is bedside clinical assessment and it suffers from being highly subjective. Its accuracy, even by experts, is only 60-80% [1-3]. Thermal burn injuries are clinically classified according to the depth of the injury as superficial, partial thickness or full thickness. Superficial burns are mild, whereby the tissueis capable of regenerating the epidermis. Full thickness injuries involve destruction of the dermal layer causing reduced blood supply that will result in ischemia and necrosis. While both superficial and full-thickness burns are typically readily diagnosed, partial thickness burns, in which a portion of the dermis is destroyed, are more difficult to classify clinically and carry considerable potential for complications. Overestimation of burn depth in partial thickness burns can result in excisional treatment, while underestimation may delay appropriate treatment, increase rate of scarring and infection, and extend duration of hospitalization and increase cost of care, in addition to exacerbating psychological sequelae for the burn patient. We propose to specifically develop SFDI within the context of assessment of burn wounds. SFDI is a wide-field imaging modality, invented at BLI, that employs patterned near infrared illumination and model based analysis methods, enabling rapid quantitative noninvasive determination of the optical properties and chromophore concentrations of tissue including oxygenated and deoxygenated hemoglobin concentration, water fraction, and reduced scattering coefficient. We hypothesize that using the information provided by SFDI, we will be able to develop burn severity indices that will enable rapid objective assessment of burn severity, with particular attention paid to partial thickness burn wounds. Specific Aims include 1) Establishment of a Swine Model of Graded Burn Severity, 2) Development of Metrics of Burn Severity based on SFDI Data, 3) Testing & Validation of a Hybrid SFDI instrument that combines both Modulated and Steady State Illumination and 4) Clinical Measurements of Burn Severity using Hybrid SFDI and SFDI derived burn severity metrics. The results of the proposed research will inform future investigations involving SFDI within the domain of burn wounds, with the ultimate objective of developing a technology that will rapidly and noninvasively provide critical insight into the severity and exten of burned tissue. Successful completion of the proposed work will lay the foundation for future longitudinal studies by providing a means for quantifying the response of tissue to new therapies that may reduce severity or extent of wounds or improve rate of healing.